The present invention relates generally to telecommunications systems and methods, and more particularly, a non-blocking, scalable optical router having an architecture that optimizes bandwidth management to allow for non-blocking switching and routing of optical data packets.
The emergence of the Internet and the reliance by business and consumers on the transfer of data in all daily activities requires telecommunications networks and components that can deliver ever increasing amounts of data at faster speeds with higher quality levels. Current telecommunications networks fail to meet these requirements.
Existing electrical and electro-optical switching routers are limited in the switching speeds that are attained and the data capacity that can be processed between switches in a non-blocking manner. Current electrical switching architectures are generally limited to a switching speed of 40-100 Gigabits. In an attempt to overcome this limitation, current electrical and optical routers use aggregation of slower switches to increase the overall switching speed of the router. For example, a system may combine a hundred one (1) Gigabit routers to increase the switching speed of the system. However, while the overall speed and capacity will exceed one Gigabit, this aggregation will not result in full 100 Gigabit per second speed and capacity, resulting in a decreased efficiency (less than full realization of switching capability). Furthermore, aggregation increases costs due to the increased number of routers and increases complexity due to interconnect and routing issues. In addition to the issues surrounding data routing speed, electronic telecommunication routing systems all face difficult transference issues when interfacing with optical data packets. Another technique used in electrical telecommunication routing systems to increase data routing speed is parallel processing. However, this technique has its own limitations including control complexity (it is difficult to control the multiple routers operating in parallel). In any of these techniques involving multiple routers to increase the processing speed, a single control machine must arbitrate among the many multiple machines which increases control complexity, cost and ultimately uses an electronic control machine that is limited by electronic processing speeds.
FIGS. 1 and 2 will illustrate the limitations of these prior art systems. FIG. 1 shows a typical prior art local network cluster 10 that uses an interconnect structure with multiple routers and switches to provide the local geographic area with a bandwidth capability greater than that possible with any one switch in the router 10. Network 10 includes four routers 12, which will be assumed to be 300 Gigabit per second routers, each of which serves a separate area of 150 Gbps of local traffic. Thus, the 300 Gigabit capacity is divided by assigning 150 Gigabits per second (Gbps) to the incoming traffic on local traffic links 16 and assigning 50 Gbps to each of three links 14. Thus, each link 14 connects the router 12 to every other router in the network 10, thereby consuming the other 150 gigabit capacity of the router 12. This interconnectivity is in the form of a xe2x80x9cmeshxe2x80x9d that allows each router 12 to communicate directly with every other router 12 in the network 10.
This configuration has a number of limitations. While the four local geographic area produce a total of 600 Gbps of capacity, the network 10 requires four routers 12 of 300 Gbps each, or 1200 Gbps of total router capacity, to provide the interconnectivity required to allow direct communication between all routers 12. Additionally, even though fully connected, each router 12 does not have access to all of the capacity from any other router 12. Thus, only one third of the local traffic (i.e., only 50 Gbps of the total potential 150 Gbps) can be switched directly from any one router 12 to another router 12, and the total potential traffic demand is 600 Gigabits per second. In order to carry more traffic over a link 14, a larger capacity would be required at each router 12 (for example, to carry all 150 Gbps over a link 14 between routers, each link 14 would need to be a 150 Gbps link and each router 12 would have to have an additional 300 Gbps capacity). Thus, to get full connectivity and full capacity, a non-blocking cluster network 10 having a mesh configuration would require routers with 600 Gbps capacity each which equates to 2400 Gbps total router capacity (or four times the combined traffic capacity of the local geographic areas).
FIG. 2 shows another prior art cluster router network 18 that aggregates sixteen data lines 20 that each can carry up to one hundred sixty gigabit per second of data that appears to have the potential capacity of 2.5 Terabits (16 lines carrying 160 Gbps each). Each of the data lines 20 is routed through an edge router 22 to an interconnected edge network 24 (e.g., a ring, mesh, ADM backbone or, other known interconnection method) via carrying lines 26. However, due to inefficiencies in this network configuration (as described above), the full potential of 2.5 Terabits cannot be achieved without a tremendous increase in the size of the edge routers 22. For example, if the edge routers are each 320 Gbps routers, then 160 Gbps is used to take incoming data from incoming data line 20 and only 160 Gbps of access remains to send data to each of the other fifteen routers 22 in the cluster 18 (i.e., approximately 10 Gbps can be allotted to each of the other fifteen routers, resulting in greater than 90% blockage of data between routers). Furthermore, the capacity of the routers is already underutilized as the overall router capacity of the network cluster 18 is 5 terabits per second (Tbps), while the data capacity actually being serviced is 2.5 Tbps. Even with the router capacity underutilized, the network 18 has over 90% blockage between interconnected routers through the edge network 24. To increase the capacity between routers in a non-blocking manner, the individual routers would need to be increased in capacity tremendously, which increases cost and further exacerbates the underutilization problems already existing in the network.
Therefore, a need exists for an optical telecommunications network and switching architecture that will provide full, non-blocking routing between service areas that allow full capacity utilization without requiring over-sized routers that result in extreme underutilization of the router capacity and tremendous increase in router costs over the network.
The present invention provides a non-blocking optical routing system and method that substantially eliminates or reduces disadvantages and problems associated with previously developed optical-routing systems and methods.
More specifically, the present invention provides a system and method for providing non-blocking routing of optical data through a telecommunications network that allows full utilization of available capacity. The network includes a number of data links that carry optical data packets to and from an optical router. The optical router includes a number of ingress edge units coupled to an optical switch core coupled further to a number of egress edge units. The ingress edge units receive the optical data packets from the data links and aggregate the optical data packets into xe2x80x9csuper packetsxe2x80x9d where each super packet is to be routed to a particular destination egress edge unit or port. The super packets are sent from the ingress edge units to an optical switch fabric within the optical switch core that routes each super packet through the optical switch fabric to the super packet""s particular destination egress edge unit in a non-blocking manner (i.e., without contention or data loss through the optical switch fabric). This routing is managed by a core controller that monitors the flow of incoming optical data packets into each ingress edge unit, controls the generation of super packets from the incoming optical data packets and transmission of super packets to the optical switch fabric, and schedules each super packet to exit the optical switch fabric so as to avoid contention among the plurality of super packets in the transmission between the optical switch fabric and the egress edge units. The core controller monitors traffic characteristics such as incoming traffic demand at each ingress edge unit, traffic routing demand to each egress edge unit, quality of service requirements, and other data to compute a scheduling pattern for sending super packets to the optical switch fabric. The core controller then schedules super packets based on the scheduling pattern (which is updated as the data traffic characteristics change). The egress edge units receive the super packets, de-aggregate (i.e., disassemble) the super packets into the optical data packets, and transmit the optical data packets to the data lines. These de-aggregated optical data packets contain the same payload as the original incoming data packets, but can potentially have different overhead data due to routing through the router.
The present invention also provides the capability of transporting super packets from the ingress edge to the optical switch core and from the optical switch core to the egress edge of the router on multiple wavelengths with each wavelength carrying a fraction of the super packet simultaneously.
The present invention provides an important technical advantage with respect to previous optical routing systems and methods by optimizing bandwidth management to provide maximum data throughput with no (or greatly reduced) data loss due to congestion or contention within or collisions between optical data packets in an optical switching core of the optical routing system.
The present invention provides another important technical advantage by providing non-blocking data processing (switching and routing) without increasing the individual router/switch capacity beyond the capacity being serviced.
The present invention provides a technical advantage by establishing a switching pattern to route data packets based on traffic requirements at any single point in the network to avoid congestion or blocking of data packets while maximizing utilization.
The present invention provides yet another technical advantage by providing an optical crossbar switch fabric that includes a unique switch path from each ingress (input) port to each egress (output) port to ensure that no blocking or congestion will occur in the switch fabric itself.
The present invention provides yet another technical advantage by aggregating the received incoming optical data packets into super packets for transport through the optical switch/router in order to optimize throughput through the switch/router. The aggregation can be an aggregation of data packets (based, for example, on destination and quality of service requirements) into all optical super packets, into all electrical super packets or perhaps even a combination of both.
The present invention is an optical telecommunications network that includes all of the technical advantages inherent in optical systems (e.g., increased speed, the ability to send multiple packets simultaneously over a single fiber, etc.).
The present invention provides another technical advantage by performing packet classification one time at the ingress edge and carrying that classification information in a classification index to the egress edge of the router. This packet classification enhances performance of a router by (i) reducing packet processing complexity at the egress edge and (ii) eliminating the classification computational requirements at the egress edge.
The present invention provides yet another technical advantage by transporting super packets between ingress and egress edge units on multiple wavelengths so that each wavelength carries a fraction of the super packet simultaneously. This advantage enhances throughput and reduces the complexity of the switch fabric of the present invention.